1. Field of the Invention
The present invention relates to harvesting machines and more particularly to conveyor means employed on such machines.
While the terms "grain" and "straw" are used principally throughout this specification for convenience, it should be understood that the terms are not intended to be limiting. Thus "grain" refers to that part of the crop material which is threshed and separated from the discardable part of the crop material which is referred to as "straw".
2. Description of the Prior Art
Conventional combine harvesters have a header and an elevator for harvesting standing crop and conveying the same to a threshing and separating mechanism for threshing and separating grain from the discardable crop material. The separated grain, together with impurities of all kind, such as chaff, dust, straw particles and tailings, are collected on a grain pan and conveyed to a cleaning mechanism comprising cleaning sieves and a cleaning fan. The cleaning mechanism is operable to discharge chaff, dust, straw particles, and the like, onto the ground and to collect the tailings in a tailings collecting mechanism and the clean grain in a clean grain collecting mechanism. The tailings are either recycled through the threshing and separating mechanism via a tailings elevator, or treated in a separate tailings re-threshing means. The clean grain is conveyed into a grain tank on top of the machine, via a grain elevator, for temporary storage. The grain elevator is normally a paddle-type elevator which extends from below and adjacent the discharge end of the clean grain collecting means in the cleaning mechanism and extends in an upward direction alongside the combine frame and often also alongside the grain tank to the top thereof or even to a location thereabove. At this upper end, the grain elevator is connected to grain distributing means extending generally transversely of the grain tank. As the grain elevator extends alongside one side of the machine frame and the grain tank, any necessary inclination can be given thereto to accommodate any fore-and-aft displacement of the grain tank relative to the cleaning mechanism without interfering with any other components of the machine.
Nowadays, there is a constant trend to increase the capacity of a combine harvester and more particularly of the grain tank. Increasing the width of the grain tank is primarily limited by road regulations imposed on all kinds of vehicles, including combine harvesters. A typical maximum permitted width is three meters. Therefore, it has already been suggested to provide a grain tank with a width of three meters. This means that, rather than providing the grain elevator alongside the grain tank side wall, it has to extend through the bottom wall and inside the grain tank. Moreover, due to the large size of such grain tanks it has become rather difficult fully and evenly to load the tanks and hence to utilize their maximum capacity with the conventional grain elevator and distributing means.